This invention relates to heat exchangers, in particular to heat exchangers for use with heat pipes or other pipes containing fluid to, or from, which heat is to be transferred.
Heat pipes are described, for example, in Australian Patent Specification No. 455,797. As described in this specification, heat pipes are passive sealed units having a working fluid with a free-standing liquid and a substantial vapour space along substantially the entire length of the heat pipe. In use, heat is automatically transferred along the pipe in response to a difference between the respective temperatures of warmer and cooler portions of the pipe. This heat transfer takes place by a process of vaporization of the working fluid in one portion of the pipe and condensation of the working fluid in another portion of the pipe thus absorbing and giving up its latent heat of vaporisation.
In heat exchangers used with heat pipes, heat transfer is achieved by flowing a transfer fluid past portion of a heat pipe to remove heat from or transmit heat to the pipe. In previously proposed heat exchangers of this type, the flow path of the transfer fluid past the heat pipe has been fairly random. For example, a plurality of heat pipes is generally enclosed in one or more chambers through which the transfer fluid is passed. The heat transfer achieved by this type of arrangement is relatively inefficient.
It is therefore an object of this invention to provide a means whereby the heat transfer efficiency of such heat exchangers may be improved and further to provide a heat transfer device which incorporates such means.